1. Field of the Invention
This invention relates to an injection molding machine, and method and more particularly to an injection molding machine and method for plastics and other similar materials having a high degree of working efficiency.
2. Discussion of the Background
Conventional injection molding machines comprise a plurality of parallel mold clamping devices, and a single movable injection device which travels along guide rails to effect injection, a pressure holding process and plasticization in regular sequence for each of the mold clamping devices.
As shown in FIG. 4, one type of this known injection molding machine comprises a movable injection device 10, two parallel guide rails 11, and three mold clamping devices 12, 13 and 14 which are stationary. As the injection device 10 travels along the guide rails 11, injection, a pressure holding process and plasticization are sequentially effected for the mold clamping devices 12, 13 and 14.
According to this known system, the movable injection device 10 injects plasticized material into the first mold clamping device 12. Immediately after injection and pressure holding process have been effected for the first mold clamping device 12, the injection device 10 starts to move to the second mold clamping device 13 while effecting plasticization.
FIG. 5 is a flow chart illustrating working processes at the respective mold clamping devices 12, 13 and 14. That is, as shown in FIG. 5, an injection molding cycle comprises the steps of closing a mold, injecting, holding pressure, cooling, opening a mold and removing a molded article.
This known injection molding system, however, has the following disadvantages. The movable injection device is not capable of starting plasticization of material for the subsequent shot until a pressure holding process for one mold clamping device is completed. Also, a large amount of starting energy or power, costly fixed equipment as well as a large space for machine installation are required to allow the injection device to make reciprocal movement along the guide rails in regular sequence.